基于MODIS/EVI的中国北方地区耕地复种指数提取

    Multiple cropping index of Northern China based on MODIS/EVI

    • 摘要: 复种是区域粮食增产的重要途径之一,也是中国粮食生产中一种重要的耕作模式。该文通过深入分析农作物的农时历和耕地的时间序列植被指数曲线的对应关系,提取了反映作物种植模式的特征时相,并以特征时相的EVI(enhanced vegetation index)值作为特征参量,构建了提取耕地复种指数的决策树方法。该方法仅用了作物生长季中7个时相来提取复种指数,减少了数据使用量,缩短了提取时间,提高了提取效率。最终,采用MODIS(moderate-resolution imaging spectroradiometer)/EVI数据,提取了2005年中国北方15个省市区的耕地复种指数,与之前的研究结果进行比较验证发现该方法具有较高的提取效率和精度。

       

      Abstract: Multiple cropping is an important mean for increasing regional grain output and also a crucial cropping pattern in China’s farming system. This study proposed a new method for extracting multiple cropping index (MCI) on pixel level with multi-temporal moderate-resolution imaging spectroradiometer (MODIS) enhanced vegetation index (EVI) data based on the crop phenology and decision tree (DT). The method could be divided into two steps. First of all, according to the local crop phenology, several features were put forward for discriminating the pixel-level MCI, which contained three types: fallow, single cropped and double cropped. Second, the threshold for each feature was brought up by using CART Algorithm. Finally, the multiple cropping index of 15 provinces of Northern China were extracted in 2005. Then, the result was compared with that of former researches, and it shows that DT method is more efficient.

       

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